Production of cyclic urea derivatives



United States Patent Office 3,538,094 Patented Nov. 3, 1970 US. Cl. 260-251 5 Claims ABSTRACT OF THE DISCLOSURE Compounds of the formula X H Ii -1T1 171-411 Ru Ir -cg O-J JOH 0 R RS/ Rl wherein R through R are alkyl of 1 to 4 carbon atoms, R can also be hydrogen, and X is oxygen or sulfur are useful as textile treating agents. The compounds are prepared by reacting the corresponding 4-oxy-2-pyrimidinone with an aldehyde, e.g., isobutyraldehyde, in the presence of a strong acid.

This invention relates to the production of cyclic urea aldehyde derivatives by reaction of cyclic hydroxyureas or alkoxyureas with aldehydes.

It is an object of this invention to provide a new method for the production, in good yields, of cyclic urea derivatives bearing an alkyl aldehyde group as substituent in the 4-position and other substituents in the 1-, 3- and 5-positions and optionally in the 6-position from easily accessible starting materials.

A further object of this invention is to provide new cyclic urea derivatives bearing an alkyl aldehyde group as substituent in the 4-position, alkyl or alkyl aldehyde groups as substituents in land 3-positions, an alkyl group in the 5-position and optionally an alkyl group in the 6-position.

In accordance with this invention these and other objects are achieved and cyclic urea derivatives having the formula:

in which R denotes an alkyl group or the radical Ra -CHz-('3GHO 1R denotes a hydrogen atom or an alkyl group, R R, R and R denote identical or different alkyl groups, are

obtained by reacting cyclic urea derivatives having the general formula:

R (II) in which R R R and R have the above meanings, R denotes a hydrogen atom or an alkyl group, with an aldehyde having the general formula:

(III) in which R and R have the above meanings, in the presence of a strong acid which is non-oxidizing under the reaction conditions and in the presence or absence of a solvent or diluent, at a temperature of from 0 to C.

The process may be represented, for example for the reaction of 1,3,5,5 tetramethyl-4-hydroxy-2-oxohexahydropyrimidine with isobutyraldehyde, by the following equation:

In the preferred starting materials (II) and consequently in the preferred end materials (I), the radical R denotes an alkyl group having preferably one to four carbon atoms or the radical:

in which R and R denote alkyl groups having one to four carbon atoms. R R R R, R and R may be identical or different alkyl radicals having one to four carbon atoms. R may also denote a hydrogen atom.

The following are examples of cyclic urea derivatives which may be used as starting materials: l,3,5,5-tetramethyl 4 hydroxy-2-oxohexahydropyrimidine, l,3,5,5- tetramethyl 4 methoxy-Z-oxohexahydropyrimidine, 1,3,5,5-tetramethyl 4 rnethoxy-6-isopropyl-2-oxohexahydriopyrimidine, 1,3-dimethyl-4-methoxy 5 ethyl-5- butyl 2-0xohexahydropyrimidine, 5,5-dimethyl-2-oxo-4- methoxyhexahydropyrimidyl 1,3 dineopentanal, N- methyl-5,5 dimethyl-6-isopropyl-4-hydroxy-2-0xohexahydropyrimidyl-N'-neopentanal.

In the aldehydes (III) which are preferred as starting materials, the radicals R and R denote identical or different alkyl groups having one to four carbon atoms. Examples of preferred aldehydes are isobutyraldehyde and 2-ethylhexanal.

Examples of strong acids which do not oxidize under the reaction conditions are hydrogen chloride, sulfuric acid, oxalic acid, benzenesulfonic acid, p-toluenesulfonic acid, or sulfonated ion exchangers. As a rule the acids are used in amounts of 1 to 100 parts by weight per mole of starting material. It is advantageous to carry out the process in the presence of solvents or diluents. For example water, ethers, such as dioxane and tetrahydrofuran, or alkanols preferably having one to four carbon atoms may be used as solvents or diluents. The solvents or diluents are used in general in an amount which is 0.1 to ten times the weight of the starting material.

The reaction of the substances is in general carried out in the theoretical molar ratio. Slight deviations from this molar ratio, for example of up to mole percent, are possible. The reaction is carried out at from 0 to 120 0., preferably at from 40 to 100 C.

The process according to the invention constitutes a condensation reaction which can be accelerated by adding more acid, with or without an increase in the reaction temperature. In many cases the urea aldehydes may be obtained in the lower temperature range in the presence of larger amounts of acid. On the other hand, the reaction may be carried out at higher temperatures in the presence of less acid. The choice of temperature depends on the reactants used; the temperature may be lower when more acid is added, and vice versa.

The new compounds having the Formula I which can be prepared by the process have textile finishing properties. They are also valuable intermediates for the production of aminoaldehydes, aminocarboxylic acids and amino resins. Thus for example cotton cloth may be impregnated therewith from an aqueous suspension for example at the rate of 80 to 200 grams of said new compounds per kilogram of fibrous material, dried and treated at elevated temperature, for example at 120 to 160 C., ginahcondensation unit and thereby given a crease-resist The invention is further illustrated by the following examples, in which parts are by weight.

EXAMPLE 1 344 parts of 2-oxo-1,3,5,S-tetramethyl-4-hydroxyhexahydropyromidine is dissolved in 1000 parts of water and in a stirred apparatus provided with good reflux cooling means 160 parts of isobutyraldehyde and 50 parts of concentrated hydrochloric acid are added. The reaction mixture is heated for eight hours at refluxing temperature and then neutralized with caustic soda solution. The mixture is shaken with chloroform, the chloroform phase is evaporated under subatmospheric pressure and the residue is fractionally distilled in a high vacuum. The main fraction has a boiling point range of from 150 to 168 C. at 0.5 to 1 mm. Hg. 260 parts of 2-oxo-1,3,5,5-tetramethylhexahydropyrimidyl-4-isobutyraldehyde is obtained.

Analysis.-Calcd for C H O N (percent) (226 C, 63.7; H, 9.7; N, 12.4. Found (percent): C, 63.4; H, 9.7; N, 12.1.

EXAMPLE 2.

326 parts of 2-oxo-4-methoxy-5,S-dimethylhexahydropyrimidyl-1,3-dineopentanal is mixed with 300 parts of dioxane and 72 parts of isobutyraldehyde in a stirred apparatus and 60 parts of 50% aqueous sulfuric acid is added while stirring. The reaction mixture is heated for five hours at 90 to 95 C. The refluxing temperature is about 70 to 75 C. at the beginning of the reaction and rises in the course of two hours to about 90 to 95 C. The mixture is cooled and neutralized with caustic soda solution. The reaction product formed is shaken with I claim: 1. A cyclic urea derivative having the formula:

0 II Rl -I]I N--Rl $6 R CH HO-CCHO (II-R4 R R in which R is alkyl of 1 to 4 carbon atoms, R is hydrogen or alkyl of 1 to 4 carbon atoms, R is alkyl of 1 to 4 carbon atoms, R is alkyl of 1 to 4 carbon atoms, R is alkyl of 1 to 4 carbon atoms, R is alkyl of 1 to 4 carbon atoms, and R is alkyl of 1 to 4 carbon atoms.

2. A cyclic urea as in claim 1 wherein R and R are methyl.

3. A process for the production of cyclic urea derivatives having the formula:

in which R is alkyl of 1 to 4 carbon atoms or the radical -0Hr i-GHO t.

R is hydrogen or alkyl of 1 to 4 carbon atoms, R and R are alkyls of 1 to 4 carbon atoms, R and R are alkyls of 1 to 4 carbon atoms which comprises: reacting a cyclic urea having the formula:

RI (II) in which R R R and R have the meanings given above, R is hydrogen or lower alkyl with a theoretical molar amount of an aldehyde having (III) in which R and R have the meanings given above in the presence of a strong acid which does not oxidize under the reaction conditions and at a temperature of from 0 to 120 C.

4. A process as in claim 3 wherein said process is carried out in the presence of a solvent selected from the group consisting of water, dioxane tetrahydrofuran, and alkanols of 1 to 4 carbon atoms.

5. A process as claimed in claim 3 carried out at from 40 to 100 C.

References Cited UNITED STATES PATENTS 2,957,028 10/1960 Brannock 260-601 3,335,187 8/1967 Hargis et a1 260-601 6 FOREIGN PATENTS 1/ 1963 Canada.

OTHER REFERENCES ALEX MAZEL, Primary Examiner RAYMOND V. RUSH, Assistant Examiner US. Cl. X.R. 252--8.8

22 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 1538;094 Dated November 3, 1970 Inventor(s) H I'O Petersen It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 61, "hydriopyr'imidine" should read uydropyrimidine Column 3, line 49, "hydropyromidine" should read hydropyrimidine a n WILLIAM E. SUHUILER, m Edwin! M. membe In commissioner or M! Anea ting Officer 

